Getting the right MVHR system makes all the difference between having something that heats your home adequately and cleans the air satisfactorily, or one that doesn’t. While a qualified team that specialises in mechanical ventilation systems may do a survey to plan what system makes sense, it’s always sensible to have a rough idea what’s required, so you can see if they’re about to make a monumental blunder.
Let’s now look at the different MVHR heat recovery units to understand more.
Counterflow for Residential Properties
While rotary heat exchanges are often best chosen for commercial offices because they humidify the air and offer greater airflow design possibilities, for residential homes this is not appropriate.
At home, it’s far better to choose a Counterflow system of heat exchangers as part of your MVHR unit. Why is this? Because they push out less airflow (but still sufficient enough for rooms that are smaller with fewer occupants at one time) which saves substantially on electricity. The heat recovery works well in recirculating heat into other rooms too.
Understanding MVHR System Requirements
Every MVHR heating system is individually planned, configured and installed. It’s not a one-stop shop where every home receives the same setup. Or… at least, it shouldn’t be!
With smaller homes, it’s possible to work out the number of litres to be extracted based on the size of the rooms. Most extraction processes take place every couple of hours from what is described as ‘wet rooms’ in the MVHR industry.
For smaller contained rooms, it’s common to see a kitchen need around a 13-litre capacity, a bathroom is less at 8 litres, and a small utility room at 8 litres too. For a home with three bathrooms, this creates a need for around a 45-litre capacity. To satisfy this, a good rule of thumb is to add two-thirds to the requirement, which boosts the system up to 75 litres.
With larger homes, the heat recovery units have more work to do because the space is greater. It’s not uncommon to have two or more units in a large living room – one at each end – to be more effective in capturing the air and recirculating it.
The calculation for larger rooms works with the square meters of the floor space and the room’s height and draws up a litre capacity requirement based on that.
Quick Thoughts on Heat Recovery Units
The reason why a higher litre capacity is recommended vs what is required based on the size of each room is because MVHR units mustn’t run at their maximum. They operate on and off throughout the day. Overloading them is not going to end well!
As such, it’s especially important to have units installed and positioned where they won’t need to run at the maximum capacity because they’re undersized for the room size. The same is true when having one larger unit installed when a small unit at either end of a larger room is a better solution.
Smart decisions when picking a MVHR system and getting it configured properly for the home size is key to a successful installation. Use a professional team, so they get it right the first time.